The present invention relates generally to disc drives. More particularly, the present invention relates to the damping of vibrations in a disc drive.
In a disc drive, there are generally two significant sources of vibration and noise: the spindle motor with the disc stack is one, and the actuator system is the other. The actuator system includes a voice coil motor, ball bearing, and a suspension-arm assembly. Seek movements of the actuator generates transient and discrete noises which is also known as seek noise. Seek noise is found to be related to the structural resonance of the head-actuator assembly. The seek noise-source level is determined by seek speed, as well as the current profile applied to the voice coil and the head-actuator dynamics. Changing the seek profile and slowing down the seek speed can reduce the levels of seek noise, however, this is at the expense of the performance of the disc drive. A more acceptable alternative is to increase the damping levels of the actuator components and so reduce the resonant behaviour while maintaining the drive performance specifications.
Viscoelastic damping materials are sometimes used to reduce vibration and noise in disc drives. Such methods have found some measure of popularity owing to the development of a wide variety of viscoelastic materials with various useful properties.
For example, some have used viscoelastic materials to dampen vibrations in the actuator system by fabricating the suspension in the form of a laminate. Others have tried cutting holes in the suspension and filling them with damping materials. However, these methods tend to raise manufacturing costs in that more expensive materials are used and manufacturing steps must be added.
What the prior art has been lacking is a damping system design that can be easily and cheaply incorporated into an actuator system, without using additional expensive components or manufacturing processes.
A disc drive includes at least one disc and at least one head configured for writing data to and reading data from the disc. The head is supported by the suspension, one end of which is attached to an actuator arm. The actuator arm extends from an actuator body, forming part of an actuator. There is provided a pre-amplifier that is operably connected to the head. The pre-amplifier is attached to a first surface of a baseplate that is directly fixed to the actuator at one point, with a damping layer between a second surface of the baseplate and the actuator. Preferably, the baseplate is restrained from rotating relative to the actuator.
These and various other features as well as advantages which characterize the present invention will be apparent upon reading of the following detailed description and review of the associated drawings.